A WEEEEE Bit Unsure!!!

[gizmo_21]

Hey Guys

I have a wiring Question:

1. I have a Clarion APX400.2M Amp and am wondering how i would like to wire it up, A Few Specs are

Cont. Power Output: 200w (100w x 2) @ 0.08% THD
2-OHM Stereo Output: 190 x 2 @ 0.05% THD
Bridged Power: 280 x 1 @ 0.05% THD

I'm running 2 Single Coil, 4 Ohm Subs.

My Suggestion is as follows (see below)

But i'm Not sure the Amp will send out a 2 ohm load if it's wired as above... could someone help me on this one????

2. What the heck does @ 0.08% or 0.05% THD Stand for (RMS????)

Here's the Manual http://safemanuals.com/user-guide-instructions-owner-manual/CLARION/APX400.2M-_E


Thanks for the help

RY

 

[colinrmitchell]

THD = Total Harmonic Distortion. It has to do with how well the output transistors in the amp can react to high-transient loads, and also their quiescent bias effects on the sound. I.e., 0.08% means that the load voltage is distorted 0.08% from its original value. You won't notice it.

Well, it says it can do 2x70W @4ohm, or 2x110W @2ohm. If you wire one speaker to each channel, you get 70W max at each speaker, since they are 4ohm. If you wire them in parallel, then you get 2ohm, but the amp can only handle 2ohm per channel, so a bridged load must be 4ohm. So it looks like you'll have to wire each speaker to an independent channel, because the amp cannot handle a 2ohm load bridged. Or get dual voice-coil speakers, so you can wire them series-parallel to get a 4ohm load.

Think of it this way. Electrically, when an amp is bridged, each channel sees "half" of the load. I.e., a 4ohm resistor would look to each channel like it was trying to drive a 2ohm resistor. So if you hooked 2ohm bridged, each channel would have to drive a 1ohm load.

Oh, and RMS means "root mean square." It's a way to consider the equal DC power consumption of an AC source. So you take your max AC voltage, multiply it by 0.707, and then divide it by your resistance (say, 4ohm), and you get your output current and power. Since sound signals are always changing, you can't state a definitive power consumption. RMS is a way to describe the constant power.

Not to bark up my own tree, but I describe some of this in detail in an article I wrote a couple of years ago when I would build power amps from scratch. If interested, follow this:
http://gozips.uakron.edu/~crm23/amplifier/amplifier.htm

Good luck!

 

[gizmo_21]

THD = Total Harmonic Distortion. It has to do with how well the output transistors in the amp can react to high-transient loads, and also their quiescent bias effects on the sound. I.e., 0.08% means that the load voltage is distorted 0.08% from its original value. You won't notice it.

Thank you... Been searchin and found a similar explaination, but for some reason yours made more sence lol...

Well, it says it can do 2x70W @4ohm, or 2x110W @2ohm. If you wire one speaker to each channel, you get 70W max at each speaker, since they are 4ohm. If you wire them in parallel, then you get 2ohm, but the amp can only handle 2ohm per channel, so a bridged load must be 4ohm. So it looks like you'll have to wire each speaker to an independent channel, because the amp cannot handle a 2ohm load bridged. Or get dual voice-coil speakers, so you can wire them series-parallel to get a 4ohm load.

Thats what i was thinking as well, so i guess my picture about wouldn't work will it???? (see this is my dads system, he just went out and got everything, and my problem is (i was just going to wire the subs straight to the amp) the box only has one set of terminals, (leaving me to wire them either as 2 ohm load or 8 ohm load) which sucks.. hmmmmmmmmmmm)

Oh, and RMS means "root mean square." It's a way to consider the equal DC power consumption of an AC source. So you take your max AC voltage, multiply it by 0.707, and then divide it by your resistance (say, 4ohm), and you get your output current and power. Since sound signals are always changing, you can't state a definitive power consumption. RMS is a way to describe the constant power.

Good luck!

Ya thats the one i know, I just though that THD was another way of describing RMS, but apparently not lol thanks so much colinrmitchell do you have any suggestions (besides buy a new system lol) for my arrangment??

Ry

 

[colinrmitchell]

Ha, you are in a pickle, it would seem. And sorry to "talk down to you," I was unsure of what you meant on question #2!

Well, There's really nothing you can do, since you can only make a 2ohm or 8ohm load. I would just hook up one sub for now at 4ohm bridged, and either leave it like that, or wait until you come across some dual-voice coil speakers.

 

[gizmo_21]

Not to bark up my own tree, but I describe some of this in detail in an article I wrote a couple of years ago when I would build power amps from scratch. If interested, follow this:
http://gozips.uakron.edu/~crm23/amplifier/amplifier.htm

WOW!!! ummmmmmmm Are you possibly and electrical engineer??? lol

 

[gizmo_21]

Ha, you are in a pickle, it would seem. And sorry to "talk down to you," I was unsure of what you meant on question #2!.

Ahhhh, don't worry i never take offense, you don't know me... i could be a genious behind this screen or i could be an absolutle fool lol!!!

Well, There's really nothing you can do, since you can only make a 2ohm or 8ohm load. I would just hook up one sub for now at 4ohm bridged, and either leave it like that, or wait until you come across some dual-voice coil speakers.

I was afraid you'd say that lol, i'm thinking i'm just going to make some new terminal posts, that way i can run it using one channel with one sub, (they aren't the greatest subs and such anyway, we got most of it for free, (that's why i don't mind drilling into the box))... hey thanks again for the help colinmitchell...

 

[colinrmitchell]

WOW!!! ummmmmmmm Are you possibly and electrical engineer??? lol

Hahaha. Actually, no! I'm a mathematician!

I just got into that as a hobby. I found all my Old Man's textbooks from the 70's and 80's and read them up (he was the elec. eng.), and started playing around with Radioshack parts before I got really hooked and started building a 1000W bass amp. I never completely finished it, but I did catch a speaker on fire with it once (it's spine-tingling power).

 

[Pistons23]

 

[gizmo_21]

well i just ended up using one channel at 2ohms,

so i wired the two 4 ohm subs to create a 2 ohm loading and stuffed it into one channel... it works.. SOUND... well it was free lol

Thanks for the help guys
RY

 

[gizmo_21]

Alrighty the Above didn't work (well it did but it kept over heating the amp)

So i guess i'll just hook one sub to one channel and have a 4 ohm loading... DAMN lol

 

[colinrmitchell]

Yeah, 2ohm is risking it. You could do it, if you didn't turn the volume up past 1/4. It's a good way to smoke some transistors (believe me, I've done it a lot). My guess is the transistors are probably cheap TO-220s with about 10A max collector current (i.e., not much). Cheap amps are usually designed to the limits normally, so anything more is risky.

What you need is another amp for the other sub!

Serious Power!

 

[gizmo_21]

Yeah, 2ohm is risking it. You could do it, if you didn't turn the volume up past 1/4. It's a good way to smoke some transistors (believe me, I've done it a lot). My guess is the transistors are probably cheap TO-220s with about 10A max collector current (i.e., not much). Cheap amps are usually designed to the limits normally, so anything more is risky.

What you need is another amp for the other sub!

Serious Power!

LOL ya i'll go scrounging for another amp... And yes i mean junk yards lol... ya that amp got really hot and turned off a couple of times... i had a feeling it might do that... but i thought i might as well try it!!! thanks again!!!